Biopharmaceutical company Insmed Pharmaceuticals Inc said that its acquisition of Celtrix Pharmaceuticals Inc has been approved by shareholders of both companies, forming Insmed Inc.

The company, which made its debut on Nasdaq on Thursday, also said that its board approved a 1-for-4 reverse stock split, and Insmed will call a special shareholders meeting to obtain approval for the reverse split.

The split will bring the outstanding common stock in line with companies of Insmed's size and market capitalisation, the company said.

Shares of Insmed were trading at 3-9/16, off its opening price of 4.